1. Field of the Invention
The present invention relates to a light emitting diode package, and, more particularly, to a high power light emitting diode package, which overcomes a problem of defects in a metal wiring structure caused by a step of a submount substrate.
2. Description of the Related Art
Generally, light emitting packages must satisfy two requirements, namely, high light emitting efficiency and excellent heat dissipation. These characteristics are very important, in particular, for high power light emitting diode packages mainly used in illuminating apparatuses.
In view of the light emitting efficiency and heat dissipation, a conventional light emitting diode employs a package which comprises a semiconductor substrate such as silicon having a cavity formed therein, as a submount substrate. One example of the light emitting diode is illustrated in FIGS. 1a and 1b. 
As shown in FIG. 1a, a conventional light emitting diode package 10 comprises a silicon submount substrate 11 having a mounting region formed thereon. The diode package 10 further comprises an insulating layer 12 such as a SiO2 layer formed on the submount substrate 11, and a metal wiring structure formed on the insulating layer 12.
As shown in FIG. 1b, the metal wiring structure comprises first and second bump pads 13a and 13b connected to respective electrodes (not shown) of a light emitting diode 18, first and second bonding pads 15a and 15b connected to external circuit, and first and second conductive lines 14a and 14b connecting the first and second bump pads 13a and 13b to the first and second bonding pads 15a and 15b, respectively.
Although silicon mainly used for the submount substrate 11 has a low thermal conductivity about a third of that of metal, it can be machined to a narrow thickness through a MEMS process, thereby ensuring a lower thermal resistance. Moreover, the mounting region has a structure wherein, after the cavity C is formed on the submount substrate 11 by typical semiconductor processing, metal reflecting plates 16 are formed at opposite sides of the cavity C. The package 10 having the metal reflecting plates 16 ensures high light emitting efficiency.
However, the conventional light emitting diode package 10 suffers defects in the wiring structure due to formation of the cavity C provided as the mounting region. That is, since the first and second conductive lines 14a and 14b are formed along inclined side walls of the cavity C, respectively, there is a high possibility of disconnection at portions (regions indicated by I and II) where the first and second bump pads 13a and 13b are connected to the first and second bonding pads 15a and 15b, respectively.
As such, the submount substrate having the cavity formed in the mounting region provides advantages in view of easy formation of the reflecting plates for enhancing the light emitting efficiency, and effective thermal dissipation by a small thickness of the portion of the substrate where the light emitting diode is mounted. However, since steps are formed on the submount substrate due to formation of the cavity, and cause disconnection, there is a limitation in manufacturing of a highly reliable light emitting diode package with such a submount substrate.